Arsenic contaminates many aquifer systems worldwide and is commonly detected in ground water at concentrations exceeding current drinking water maximum contaminant levels. Arsenic is associated with a number of adverse effects on human health and is considered to be a human carcinogen.
Arsenic is a redox-sensitive element. As a result, arsenic may be present in a variety of redox states. In most aquifer and ground water systems having arsenic (As), the arsenic species are generally present as arsenate (As5+) or arsenite (As3+).